﻿// Study0315.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
// 第三章 函数 系统函数

#include <iostream>

#include <cmath> //声明cmath的头文件

using namespace std;

const double PI = 3.14159265358979;



int main() {

    double angle;

    cout << "Please enter an angle: ";

    cin >> angle;  //输入角度值

    double radian = angle * PI / 180; //转为弧度

    cout << "sin(" << angle << ") = " << sin(radian) << endl;

    cout << "cos(" << angle << ") = " << cos(radian) << endl;

    cout << "tan(" << angle << ") = " << tan(radian) << endl;

    return 0;

}
